PseudoVolumeTexture inverted on GL

UDN report:

Hi, This is not really a question, but I just wanted to point something. It seems that the PseudoVolumeTexture method in common.ush is not working the same way between DirectX and OpenGL builds. A texture will be sampled correctly in the DirectX build and not in the OpenGL ES build depending on how the asset was exported (Y-Axis direction up or down).

A work around for this was to reimplement the method with a macro to invert the Y sample position.

Trivial Fix.

Rough steps, no easy test case:

• Create a Niagra particle system in a new scene
• Create a new material with Sample Pseudo Volume Texture node
• Add volume texture
• Feed parameters into new node (can be time based for test)
• Run on Windows and Android, result should match